On 12.12.23 09:52, lukas.funke-oss@weidmueller.com wrote:
From: Lukas Funke lukas.funke@weidmueller.com
This series enables the 'setexpr' command to print "cpu list"-like bitmaps based on the printk format specifier [1].
One use-case is to pass cpu list [2] based kernel parameter like 'isolcpu', 'nohz_full', irq affinity or RCU related CPU parameter to the kernel via a separate firmware variable without exposing the 'bootargs' variable to directly.
Example:
setexpr isolcpu_bootarg=%32pbl $myCPUisolation
I applied your patches on top of origin/next but your example simply does not work:
=> setenv myCPUisolation 123456789abcdef0 => setexpr isolcpu_bootarg=%32pbl $myCPUisolation ## Error: illegal character '='in variable name "isolcpu_bootarg=%32pbl"
This produces some output:
=> setexpr a fmt '%32pbl' 64; echo $a 6
But the result is completely unexpected. Number arguments in U-Boot are always hexadecimal. So the output should be
2,5-6
Best regards
Heinrich
&& env set bootargs "$isolcpu_bootarg" && bootm
[1] https://www.kernel.org/doc/Documentation/printk-formats.txt [2] https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html
Changes in v2:
- Add bitmap format specifier to documentation
Lukas Funke (6): sandbox: add generic find_next_zero_bit implementation linux: bitmap.h: add 'for_each_set_bitrange' iteration macro test: cmd: setexptr: Add tests for bitmap string format doc: printf() codes: Add bitmap format specifier lib: vsprintf: enable '%*pb[l]' format specifier cmd: printf: forward '%p' format string specifier
arch/sandbox/include/asm/bitops.h | 16 ++++++- cmd/printf.c | 29 ++++++++++++ doc/develop/printf.rst | 6 +++ include/linux/bitmap.h | 7 +++ lib/vsprintf.c | 75 +++++++++++++++++++++++++++++++ test/cmd/setexpr.c | 9 ++++ 6 files changed, 140 insertions(+), 2 deletions(-)